T 1D -weighted ihMT imaging - Part I. Isolation of long- and short-T 1D components by T 1D -filtering.

Autor: Hertanu A; Aix Marseille Univ, CNRS, CRMBM, Marseille, France.; APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France., Soustelle L; Aix Marseille Univ, CNRS, CRMBM, Marseille, France.; APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France., Le Troter A; Aix Marseille Univ, CNRS, CRMBM, Marseille, France.; APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France., Buron J; Aix Marseille Univ, CNRS, CRMBM, Marseille, France.; APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France.; Aix Marseille Univ, CNRS, IBDM, Marseille, France., Le Priellec J; Aix Marseille Univ, CNRS, IBDM, Marseille, France., Carvalho VND; Aix Marseille Univ, CNRS, CRMBM, Marseille, France.; APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France.; Aix Marseille Univ, CNRS, ICR, Marseille, France., Cayre M; Aix Marseille Univ, CNRS, IBDM, Marseille, France., Durbec P; Aix Marseille Univ, CNRS, IBDM, Marseille, France., Varma G; Division of MR Research, Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA., Alsop DC; Division of MR Research, Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA., Girard OM; Aix Marseille Univ, CNRS, CRMBM, Marseille, France.; APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France., Duhamel G; Aix Marseille Univ, CNRS, CRMBM, Marseille, France.; APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France.
Jazyk: angličtina
Zdroj: Magnetic resonance in medicine [Magn Reson Med] 2022 May; Vol. 87 (5), pp. 2313-2328. Date of Electronic Publication: 2022 Jan 17.
DOI: 10.1002/mrm.29139
Abstrakt: Purpose: To identify T 1D -filtering methods, which can specifically isolate various ranges of T 1D components as they may be sensitive to different microstructural properties.
Methods: Modified Bloch-Provotorov equations describing a bi-T 1D component biophysical model were used to simulate the inhomogeneous magnetization transfer (ihMT) signal from ihMTRAGE sequences at high RF power and low duty-cycle with different switching time values for the dual saturation experiment: Δt = 0.0, 0.8, 1.6, and 3.2 ms. Simulations were compared with experimental signals on the brain gray and white matter tissues of healthy mice at 7T.
Results: The lengthening of Δt created ihMT high-pass T 1D -filters, which efficiently eliminated the signal from T 1D components shorter than 1 ms, while partially attenuating that of longer components (≥ 1 ms). Subtraction of ihMTR images obtained with Δt = 0.0 ms and Δt = 0.8 ms generated a new ihMT band-pass T 1D -filter isolating short-T 1D components in the 100-µs to 1-ms range. Simulated ihMTR values in central nervous system tissues were confirmed experimentally.
Conclusion: Long- and short-T 1D components were successfully isolated with high RF power and low duty-cycle ihMT filters in the healthy mouse brain. Future studies should investigate the various T 1D -range microstructural correlations in in vivo tissues.
(© 2022 International Society for Magnetic Resonance in Medicine.)
Databáze: MEDLINE
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